CY74FCT191T - Presettable Synchronous 4-Bit Up/Down Binary Counters

The CY74FCT191T is a reversible modulo-16 binary counter, featuring synchronous counting and asynchronous presetting. The preset allows the CY74FCT191T to be used in programmable dividers. The count enable input, terminal count output, and ripple-clock output make possible a variety of methods of implementing multiusage counters. In the counting modes, state changes are initiated by the rising edge of the clock.

This device is fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

• Function, Pinout, and Drive Compatible With FCT and F Logic
• Reduced V_OH (Typically = 3.3 V) Versions of Equivalent FCT Functions
• Edge-Rate Control Circuitry for Significantly Improved Noise Characteristics
• I_off Supports Partial-Power-Down Mode Operation
• ESD Protection Exceeds JESD 22
  • 2000-V Human-Body Model (A114-A)
  • 200-V Machine Model (A115-A)
  • 1000-V Charged-Device Model (C101)
• Matched Rise and Fall Times
• 64-mA Output Sink Current
  32-mA Output Source Current